4A-GE doesn't want to rev
Discussion
My '84 MR2 has a problem that is bugging the hell out of me - I'm hoping someone can give me a few pointers.
It starts fine and goes great at low revs and small throttle openings. No problem there.
If I go WOT at low revs, it's 'lumpy' and hesitates, and there isn't a whole lot of urge. If I back off the throttle, it picks up again.
Once I get to ~4,000 RPM, it's really not happy - it doesn't want to rev at all, there's no power, nothing. Like when you get near the rev limit in a diesel.
It used to pull cleanly to the redline, but has been getting progressively worse over the last year or so.
It's a 'redtop' engine (late 80's - no TVIS), but with the original 'bluetop' ECU and injectors. What else...no blue smoke on acceleration, so compression should be ok. Plugs, oil/filter and air filter were all changed in the last year.
It starts fine and goes great at low revs and small throttle openings. No problem there.
If I go WOT at low revs, it's 'lumpy' and hesitates, and there isn't a whole lot of urge. If I back off the throttle, it picks up again.
Once I get to ~4,000 RPM, it's really not happy - it doesn't want to rev at all, there's no power, nothing. Like when you get near the rev limit in a diesel.
It used to pull cleanly to the redline, but has been getting progressively worse over the last year or so.
It's a 'redtop' engine (late 80's - no TVIS), but with the original 'bluetop' ECU and injectors. What else...no blue smoke on acceleration, so compression should be ok. Plugs, oil/filter and air filter were all changed in the last year.
Ok, I put a new fuel filter in (which is a right fiddly job on the MR2), and it hasn't made a whole lot of difference. The plugs are still grey after a good thrash.
Is there an easy way to check the pump and/or regulator? Getting to the pump is a bit of a mission.
It doesn't feel like a misfire, but it never hurts to check the ignition I guess.
Another bit of info - the base of the plug threads were they poke into the chamber are matt black and sooty - I think this means oil getting past the valve guides? Could this be related in some way, or is that a separate issue?
Thanks again for the replies so far.
Is there an easy way to check the pump and/or regulator? Getting to the pump is a bit of a mission.
It doesn't feel like a misfire, but it never hurts to check the ignition I guess.
Another bit of info - the base of the plug threads were they poke into the chamber are matt black and sooty - I think this means oil getting past the valve guides? Could this be related in some way, or is that a separate issue?
Thanks again for the replies so far.
Ok, a bit more info. I pulled the vacuum pipe off the FPR with the engine warmed up and idling, and it made bu@@er all difference - no change in idle speed. No fuel spurting out either though, so at least the diaphram is ok.
I then blocked up the vaccum pipe (still disconnected) and went for a drive. I honestly couldn't notice any difference.
Does that indicate a stuffed FPR?
I then blocked up the vaccum pipe (still disconnected) and went for a drive. I honestly couldn't notice any difference.
Does that indicate a stuffed FPR?
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